jch@batcomputer.tn.cornell.edu (Jeffrey C Honig) (11/09/89)
Can someone recommend good density and size parameters for use with dump on the 150Mbyte cartridge drives. Thanks. Jeff
silver@s.cs.uiuc.edu (11/11/89)
I assume you mean for the standard tape drive, numbered 6157-002. I've been using -C2000 (2000*512 byte = 1Meg size clusters) and the prformance in quite good. I've never fiddled with the density, as 700 (or is it 500) is the default, and I'm sure it was chosen for a good reason :-). The -C<#> default is 1 (if memory serves me). The time to fill a 125-150Meg tape is about 25-35 minutes with the -C2000 parameter. May you never have to use any of the backups you make. Edward A. Silverstein silver@director.beckman.uiuc.edu
peter@hydrovax.nmt.edu (Peter A. Blemel) (11/13/89)
In article <213600005@s.cs.uiuc.edu>, silver@s.cs.uiuc.edu writes... > >I assume you mean for the standard tape drive, numbered 6157-002. > >I've been using -C2000 (2000*512 byte = 1Meg size clusters) and the >prformance in quite good. Using: tar cvfC /dev/rmt0 2000 args... yeilds: 'tar: Cluster size reduced to 800'. Am I doing something wrong? Peter ----- peter@hydrovax.nmt.edu peter@amber.nmt.edu
luner@werewolf.CS.WISC.EDU (David L. Luner) (11/14/89)
In article <213600005@s.cs.uiuc.edu> silver@s.cs.uiuc.edu writes: >May you never have to use any of the backups you make. I'm posting the following ancedote for amusement value, not as a plug for either IBM or 3M. The story is true and was related to me by the individual involved. In the path of the hurricane Hugo that swept through North Carolina this year was an RT in a first floor office. Well, needless to say, things were a mess. There were "high water" marks 7 feet up the wall. The RT, alas, was history. No problem, they figure because (1) They had RT systems ready to ship from the "home office" Fine. Within 24 hours, a new system has arrived. (2) They had backup tapes stored off-site Wrong. The backup takes stored off-site were (1) 8 months old and ... (2) blank. So Jim went down to see what he could do. In a supply cabinet he found the on-site backup tapes. Standard 3M cartridges, in the plastic containers completely caked with sludge. At this point, clearly with nothing to loose, Jim takes a tape back to his hotel room, opens up the cartridge and spends the night running warm water (or what passed for water) over the tape. Note: the tape was not unwound as a tightly wound tape is fairly waterproof on the inside. After carefully drying the tape and putting the cartridge back together he brings the tape in the next day and, lo, it is readable. Note: The remaining tapes were successfully recovered by a less colourful process. 3M has a service (I don't know about charges) for cleaning tapes that have need accidently maimed. The net result is that the site was up an running as of their last backup. -- David PS. Please take backups, verify them and store them off-site. Don't call me for hurricanes.